A state, usually experienced by straight males, of being so totally engrossed in the contemplation of a lady's rather fine breasts that you don't realise that you've been completely taken advantage of. Usually results in a man's total compliance and agreement to anything.
A word-relative of pussywhipped.

"Why on earth did you agree to drive her all the way home?"
"Well, to be honest mate, I was completely tit-whipped at that point and would have said 'yes' to anything..."